I'm glad you said it too. There always seems to be "som ting wong" when I say it.
Good quality 1.5 roller rockers?
- Thread starter midnight340
- Start date
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I'm glad you said it too. There always seems to be "som ting wong" when I say it.
j par
Well-hung Member
per triple R...
View attachment 1715363157
Exactly! You can actually do that with a hand file if you are patient enough.
j par
Well-hung Member
That's what I did....
yellow rose
Overnight Sensation
You need to send those pictures to Mike at B3 and see what he says. There is NO WAY, no POSSIBLE way that geometry is correct with that much lift.
I could be wrong, but I doubt it.
I understand that the pallet style rocker won't have a sweep pattern of a roller but that has to be damn near .300 wide. Or close to it.
I'll say it again, Chrysler guys need to spend more time with geometry. It's now relatively simple to correct. Your issue is going to be pushrod length.
It's worth a call to Mike and see what he says. That pattern is WAY too wide for my taste.
Again, if you change any part of the valve train, such as lift, or stem height etc. you need to correct for that. The stand height and placement was dictated by a lift of what? .450 lift? You've added a .100 to that.
mullinax95
Well-Known Member
B3 sent me PRW roller rockers with geo kit. For the money spent they work great and have seen some 6500 RPM blast more than once.
famous bob
mopar misfit
I am no expert, but that looks WAY , WAY wide to me !!
nm9stheham
Well-Known Member
It is logical that the walk across the valve stem would be more with such and increase of lift over the stock range as noted. (Hence the thought that shaft needs lowering.)
FWIW.... I've tested the 273 and stamped rockers for rocker ratio up to .500" when installed on a stock 675 head and watched the contact point walk across the valve stem. It moves quite a bit. Yes you are right.....I shoulda taken pix!
IMHO, part of why the OP's contact patch is moving out so far to the exhaust side is that his lift is going so far beyond the stock lifts for which these were designed. The range of the 'walk' has a lot to do with the curvature ground on the pad, and he is going well beyond what that was designed for. I don't necessarily think moving the shaft is going to change the contact patch/walk width. To reduce this, the pad would have to have the curvature of the pad changed. (Ground towards the outer edge with more curvature, I think.)
But the curvature of the pad also controls the degree of slippage that has to occur between the rocker pad and the valve tip, which effects the side force on the valve stem. (Which a roller tip gets rid of.) So it is a compromise, and I would bet the 273 rocker's curvature is set for lower lift AND limited slippage of the rocker on tip for durabilty of the stock valves and guides.
Redesigning that curvature AND then regrinding the curvature would be beyond a backyard mechanic's capabilities, and even most good shops. Something like the Crane rockers would probably have that pad curvature increased from what is on the 273 lifters, for better contact control at higher lifts, with the compromise of more slippage and side force.... which would be typically be thought of as an OK compromise in a modified engine.
FWIW.... I've tested the 273 and stamped rockers for rocker ratio up to .500" when installed on a stock 675 head and watched the contact point walk across the valve stem. It moves quite a bit. Yes you are right.....I shoulda taken pix!
IMHO, part of why the OP's contact patch is moving out so far to the exhaust side is that his lift is going so far beyond the stock lifts for which these were designed. The range of the 'walk' has a lot to do with the curvature ground on the pad, and he is going well beyond what that was designed for. I don't necessarily think moving the shaft is going to change the contact patch/walk width. To reduce this, the pad would have to have the curvature of the pad changed. (Ground towards the outer edge with more curvature, I think.)
But the curvature of the pad also controls the degree of slippage that has to occur between the rocker pad and the valve tip, which effects the side force on the valve stem. (Which a roller tip gets rid of.) So it is a compromise, and I would bet the 273 rocker's curvature is set for lower lift AND limited slippage of the rocker on tip for durabilty of the stock valves and guides.
Redesigning that curvature AND then regrinding the curvature would be beyond a backyard mechanic's capabilities, and even most good shops. Something like the Crane rockers would probably have that pad curvature increased from what is on the 273 lifters, for better contact control at higher lifts, with the compromise of more slippage and side force.... which would be typically be thought of as an OK compromise in a modified engine.
midnight340
Well-Known Member
Well, given that I am interested in valve train longevity, it appears to me that I'd better just order up a set of roller rockers and kit from Mike at B3 (whatever he recommends.) I don't know yet how quickly I could get a set, but will call him tomorrow and check on it. The next thing would be getting a set of pushrods. Hoping I can solve this rather quickly.
The best bang for the buck ! 7500 and change a few times with the 451.
mullinax95
Well-Known Member
If you get the geometry kit you'll have to give Mike some measurements of the valve stem height to shafts. At least I had to. Then he'll work on your geo kit and send it out with your rockers. It didn't take him long to get them to me.
yellow rose
Overnight Sensation
There's nothing wrong with your rockers. I've never seen a need to lower a shaft.
That's why you need to call Mike. He may tell you I'm off the reservation. It's not really a rocker issue.
midnight340
Well-Known Member
Monday update:
1) FIRST, my apologies, as my rockers ARE spot faced correctly! I was sure the image in my head was correct when I wrote that they were not, ...but I checked today, and that part is good.
2) Mike at B3 called me back first thing this morning and we talked over options. He thinks that I'm fine staying with the 273 rockers for now as long as I can solve the adjusters staying tight. (He had checked in on this thread.) I will send him the info he needs to see what might be needed for possibly getting a set of 1.5 rollers in the future. Thanks, Mike!!!!
3) "Doc" at Automotive Machine and Performance (great Mopar oriented shop) here in Lawrence, KS thinks likely I'm just not getting the adjuster lock nuts torqued tight enough, and said that I likely need 30-35 lbs on them, which is more than I was doing. He handed me a set of ARP 12-point lock nuts which being taller give me an easier time getting a wrench on them. (The others were the low flat kind from Comp.)
4) And Gary at Rocker Arms Unlimited in Redding, CA is sending me two extra re-bushed and prepped replacement arms so I swap out the one or two with excessively loose adjuster threads.
So many great people, here on this forum, and other helpful and knowledgeable folks, all dedicated to keeping these old Mopars running. Just how cool is that?!!!!
1) FIRST, my apologies, as my rockers ARE spot faced correctly! I was sure the image in my head was correct when I wrote that they were not, ...but I checked today, and that part is good.
2) Mike at B3 called me back first thing this morning and we talked over options. He thinks that I'm fine staying with the 273 rockers for now as long as I can solve the adjusters staying tight. (He had checked in on this thread.) I will send him the info he needs to see what might be needed for possibly getting a set of 1.5 rollers in the future. Thanks, Mike!!!!
3) "Doc" at Automotive Machine and Performance (great Mopar oriented shop) here in Lawrence, KS thinks likely I'm just not getting the adjuster lock nuts torqued tight enough, and said that I likely need 30-35 lbs on them, which is more than I was doing. He handed me a set of ARP 12-point lock nuts which being taller give me an easier time getting a wrench on them. (The others were the low flat kind from Comp.)
4) And Gary at Rocker Arms Unlimited in Redding, CA is sending me two extra re-bushed and prepped replacement arms so I swap out the one or two with excessively loose adjuster threads.
So many great people, here on this forum, and other helpful and knowledgeable folks, all dedicated to keeping these old Mopars running. Just how cool is that?!!!!
Monday update:
1) FIRST, my apologies, as my rockers ARE spot faced correctly! I was sure the image in my head was correct when I wrote that they were not, ...but I checked today, and that part is good.
2) Mike at B3 called me back first thing this morning and we talked over options. He thinks that I'm fine staying with the 273 rockers for now as long as I can solve the adjusters staying tight. (He had checked in on this thread.) I will send him the info he needs to see what might be needed for possibly getting a set of 1.5 rollers in the future. Thanks, Mike!!!!
3) "Doc" at Automotive Machine and Performance (great Mopar oriented shop) here in Lawrence, KS thinks likely I'm just not getting the adjuster lock nuts torqued tight enough, and said that I likely need 30-35 lbs on them, which is more than I was doing. He handed me a set of ARP 12-point lock nuts which being taller give me an easier time getting a wrench on them. (The others were the low flat kind from Comp.)
4) And Gary at Rocker Arms Unlimited in Redding, CA is sending me two extra re-bushed and prepped replacement arms so I swap out the one or two with excessively loose adjuster threads.
So many great people, here on this forum, and other helpful and knowledgeable folks, all dedicated to keeping these old Mopars running. Just how cool is that?!!!!
Well good. I was gonna say ask Mike his opinion of which rocker to run, but it sounds like you got it handled for now at least. Maybe you won't need to buy more rockers after all.
yellow rose
Overnight Sensation
Monday update:
1) FIRST, my apologies, as my rockers ARE spot faced correctly! I was sure the image in my head was correct when I wrote that they were not, ...but I checked today, and that part is good.
2) Mike at B3 called me back first thing this morning and we talked over options. He thinks that I'm fine staying with the 273 rockers for now as long as I can solve the adjusters staying tight. (He had checked in on this thread.) I will send him the info he needs to see what might be needed for possibly getting a set of 1.5 rollers in the future. Thanks, Mike!!!!
3) "Doc" at Automotive Machine and Performance (great Mopar oriented shop) here in Lawrence, KS thinks likely I'm just not getting the adjuster lock nuts torqued tight enough, and said that I likely need 30-35 lbs on them, which is more than I was doing. He handed me a set of ARP 12-point lock nuts which being taller give me an easier time getting a wrench on them. (The others were the low flat kind from Comp.)
4) And Gary at Rocker Arms Unlimited in Redding, CA is sending me two extra re-bushed and prepped replacement arms so I swap out the one or two with excessively loose adjuster threads.
So many great people, here on this forum, and other helpful and knowledgeable folks, all dedicated to keeping these old Mopars running. Just how cool is that?!!!!
Mike didn't think that sweep was too wide?
midnight340
Well-Known Member
As I understand it, he also talked about the way the non-roller stock adjustable arms "walk" across the valve as designed, with some slip at the ends of the walk, and since I am putting a bunch more lift to them there will be a bit more at both ends of the travel. But basically they are doing what they were designed to do. with the curve of the pad, they kinda roll across the surface. It's nothing like what happens with a roller.
yellow rose
Overnight Sensation
Wyrmrider
Well-Known Member
Try some lash caps and check the sweep
if stock was for 450 lift and you go to 550 but all the extra lift is down from the stock 450 lift location
raising the valve tip .050 would give you up .050 and then the additional 100down would put the tip down an extra .050 instead of .100 should put the geometry back to stock (of course different length valves or sunk seats make imperfect science)
so see if a lash cap makes problem better or worse- might tell you which way to go
BTW YR doing the mid lift gives you equal up and down angles which gives you the narrowest scribe which is what OP needs to achieve
most of my experience was with long valves and aluminum stands but I can see that moving the shaft down with stock/ 273 rockers would give same effect as a lash cap
way different than roller rockers where anything less than up and back just gives funny results (bad things happen)
if stock was for 450 lift and you go to 550 but all the extra lift is down from the stock 450 lift location
raising the valve tip .050 would give you up .050 and then the additional 100down would put the tip down an extra .050 instead of .100 should put the geometry back to stock (of course different length valves or sunk seats make imperfect science)
so see if a lash cap makes problem better or worse- might tell you which way to go
BTW YR doing the mid lift gives you equal up and down angles which gives you the narrowest scribe which is what OP needs to achieve
most of my experience was with long valves and aluminum stands but I can see that moving the shaft down with stock/ 273 rockers would give same effect as a lash cap
way different than roller rockers where anything less than up and back just gives funny results (bad things happen)
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